Dietary Guanidine Acetic Acid Improves Ruminal Antioxidant Capacity and Alters Rumen Fermentation and Microflora in Rapid-Growing Lambs

Abstract

Guanidine acetic acid (GAA) has been reported to improve growth performance, nutrient utilization, and meat quality in livestock. This study aimed to investigate whether coated GAA (CGAA) in comparison with uncoated GAA (UGAA) could have different effects on rumen fermentation, antioxidant capacity, and microflora composition in the rumen. Seventy-two lambs were randomly arranged in a 2 × 3 factorial experiment design with two diets of different forage type (OH: oaten hay; OHWS: oaten hay plus wheat silage) and three GAA treatments within each diet (control, diet without GAA addition; UGAA, uncoated GAA; CGAA, coated GAA). The whole feeding trial lasted for 120 days. The lambs in the OH group presented lower total volatile fatty acid (VFA), alpha diversity, Firmicutes, NK4A214_group, and Lachnospiraceae_NK3A20_group than those on the OHWS diet in the last 60 days of the feeding stage (p < 0.05). Regardless of what GAA form was added, dietary GAA supplementation increased the total VFA, microbial crude protein (MCP), adenosine triphosphate (ATP), and antioxidant capacity in rumen during lamb feedlotting (p < 0.05). However, molar propionate proportion, acetate:propionate ratio (A:P), and relative Succiniclasticum abundance decreased with GAA addition in the first 60 days of the growing stage, while the molar butyrate proportion and NK4A214_group (p < 0.05) in response to GAA addition increased in the last 60 days of feeding. These findings indicated that dietary GAA enhanced antioxidant capacity and fermentation characteristics in the rumen, but the addition of uncoated GAA in diets might cause some dysbacteriosis of the rumen microbiota.

Effect of Guanidinoacetic Acid Supplementation on Growth Performance, Rumen Fermentation, Blood Indices, Nutrient Digestion, and Nitrogen Metabolism in Angus Steers

“…In our study, the addition of GAA increased CAT levels and decreased MDA levels in the blood of Angus steers, suggesting that GAA enhanced the antioxidant capacity of steers. This is consistent with previous studies [18]. Creatine has been reported to have the ability to remove O2- [44], and the changes in creatine concentration in this study coincided with the changes in antioxidant indices.…”

“…This process involves not only energy metabolism but also N deposition (nitrogen metabolism) in the beef cattle organism [17]. In addition, GAA has been reported to enhance the antioxidant capacity of the rumen in ruminants [18]. In summary, GAA has the potential to improve growth performance in ruminants, but little is known about the effects of GAA on production performance and nitrogen metabolism in Angus steers; furthermore, it remains to be explored whether the addition of high doses of GAA would have a linear superimposed effect on the metrics in Angus steers.…”

The Effect of Guanidinoacetic Acid Addition on In Vitro Rumen Fermentation Characteristics and Gas Production of Early- and Late-Stage Sheep-Fattening Diets

“…The increase in TVFA production was in line with the bacteria populations [31], indicating that GAA addition has a positive influence on nutrient degradation and microbial growth [41]. However, the introduction of excessive GAA may have inhibited TVFA production, this may be related to the effect of GAA overdose on rumen homeostasis [42], and it suggests that GAA coating is necessary for ruminants. However, we did not observe a change in the proportion of individual volatile acids, and this finding is inconsistent with the research on cows, which has demonstrated that GAA can alter the fermentation pattern and promote the formation of propionic acid [31]; this may be related to a lower NDF of the basal diet [43].…”

Effect of Dietary Guanidinoacetic Acid Levels on the Mitigation of Greenhouse Gas Production and the Rumen Fermentation Profile of Alfalfa-Based Diets

“…However, it has been reported that the addition of GAA in the diet can decrease the asymptotic production and the production rate of GP [44], which was observed in the AH100 diet when increasing the dose of GAA, which is attributed to the proportion of short-chain fatty acids (SCFA), since GAA favors the formation of propionate [45], an SCFA that produces less gas compared to acetate and butyrate [46]. In addition, the lag phase also increased in this diet; although it did not show a trend with an increasing dose of GAA, this increase can be attributed to the time that ruminal microorganisms require to adapt to the presence of GAA, since it is susceptible to degradability when it is not rumen protected [47], and microorganisms can use it as a source of energy and nitrogen to synthesize their proteins [45]. However, with an increase in GAA, GP production increased in the AH10 diet, while in the AH100 diet, GP production decreased with increased GAA dose.…”